APPENDIX 359 



two natural species. A family or strain can be formed 

 only by inbreeding, and it is here that we find the key to 

 the situation. 



Although long practised by progressive breeders, con- 

 sanguinity is still abhorred by many, which perhaps ac- 

 counts for the "fact that progress in every breed of domestic 

 animals is made by a very few leaders, the majority being 

 engaged in producing mediocre specimens. Inbreeding is 

 believed by many to lead at once to ruin and chaos. This 

 belief is not entirely without foundation, for there can be 

 no doubt that, improperly practised, no system of breed- 

 ing will more quickly ruin a stock. A touch of consanguin- 

 ity brings out whatever of good or evil is in the strain and 

 any inherent weakness is at once intensified. In domestic 

 animals there is always present a tendency toward sterility. 

 Injudicious inbreeding increases this condition and quickly 

 brings about total lack of fertility. On the other hand, there 

 is no evidence to show that consanguinity itself can pro- 

 duce any bad effect, and there is much to prove that in union 

 with the most rigid selection, every good point of the breed 

 in question can be firmly established and improved and the 

 undesirable eliminated. 



Inbreeding, reduced to a system, is known as line breed- 

 ing. There are many forms and variations, but an explana- 

 tion of the typical one will suffice. A selected pair, chosen 

 for vigor, high quality and freedom from bad faults, are 

 mated together. From their offspring the finest male is 

 mated to the mother and the finest female to the father. 

 This process may be repeated and the best of the grand- 

 children remated to the original parents, or the former may 

 be crossed among themselves. The last method might be con- 

 sidered the better, for while the grandchildren contain three- 

 quarters of the blood of the original male on one side and 

 the same quantity of that of the female on the other, when 



